user32: Check invalid device names in ChangeDisplaySettingsExW().

dlls/user32/sysparams.c

@@ -3307,7 +3307,8 @@ static BOOL is_detached_mode(const DEVMODEW *mode)
 LONG WINAPI ChangeDisplaySettingsExW( LPCWSTR devname, LPDEVMODEW devmode, HWND hwnd,
                                       DWORD flags, LPVOID lparam )
 {
-    WCHAR primary_adapter[CCHDEVICENAME];
+    WCHAR primary_adapter[CCHDEVICENAME], *end;
+    long int display_idx;
     BOOL def_mode = TRUE;
     DEVMODEW dm;
     LONG ret;
@@ -3331,6 +3332,19 @@ LONG WINAPI ChangeDisplaySettingsExW( LPCWSTR devname, LPDEVMODEW devmode, HWND
         devname = primary_adapter;
     }
 
+    if (strncmpiW(devname, ADAPTER_PREFIX, ARRAY_SIZE(ADAPTER_PREFIX)))
+    {
+        ERR("Invalid device name %s.\n", wine_dbgstr_w(devname));
+        return DISP_CHANGE_BADPARAM;
+    }
+
+    display_idx = strtolW(devname + ARRAY_SIZE(ADAPTER_PREFIX), &end, 10);
+    if (*end || display_idx < 1)
+    {
+        ERR("Invalid device name %s.\n", wine_dbgstr_w(devname));
+        return DISP_CHANGE_BADPARAM;
+    }
+
     if (devmode)
     {
         trace_devmode(devmode);

dlls/user32/tests/monitor.c

@@ -369,13 +369,13 @@ static void test_ChangeDisplaySettingsEx(void)
     ok(res, "EnumDisplaySettingsA failed, error %#x\n", GetLastError());
 
     res = ChangeDisplaySettingsExA("invalid", &dm, NULL, CDS_TEST, NULL);
-    todo_wine ok(res == DISP_CHANGE_BADPARAM, "ChangeDisplaySettingsA returned unexpected %d\n", res);
+    ok(res == DISP_CHANGE_BADPARAM, "ChangeDisplaySettingsA returned unexpected %d\n", res);
 
     res = ChangeDisplaySettingsExA("\\\\.\\DISPLAY0", &dm, NULL, CDS_TEST, NULL);
-    todo_wine ok(res == DISP_CHANGE_BADPARAM, "ChangeDisplaySettingsA returned unexpected %d\n", res);
+    ok(res == DISP_CHANGE_BADPARAM, "ChangeDisplaySettingsA returned unexpected %d\n", res);
 
     res = ChangeDisplaySettingsExA("\\\\.\\DISPLAY1\\Monitor0", &dm, NULL, CDS_TEST, NULL);
-    todo_wine ok(res == DISP_CHANGE_BADPARAM, "ChangeDisplaySettingsA returned unexpected %d\n", res);
+    ok(res == DISP_CHANGE_BADPARAM, "ChangeDisplaySettingsA returned unexpected %d\n", res);
 
     /* Test dmDriverExtra */
     memset(&dm, 0, sizeof(dm));